1. Field of the Invention:
The present invention generally relates to batteries and more particularly to primary batteries of the remotely activated type which utilize one or more zinc electrodes.
2. Prior Art:
The usual types of primary batteries of the remotely activated type intended for single use and employing zinc and silver oxide electrodes normally are activated by adding alkaline electrolytes thereto. Such batteries exhibit inferior properties at temperatures of between about -10.degree. C and about -50.degree. C. For example, it is impossible to activate such a primary battery at a temperature of -20.degree. C to the rated voltage for the battery within a time of less than one second. It is believed that the reason for the long activation time is because that is the length of time at that temperature needed to dissolve the passivation coat on the zinc in the electrolyte and thus permit full activation of the battery. The passivation coat time increases as the cell temperature is decreased. Thus, such time increases from about one second at -20.degree. C to about 30 seconds at -40.degree. C when the zinc electrodes used in the battery have been manufactured by electrolytic deposition. There are many potential uses for such primary batteries which uses require activation times far less than those encountered with the existing primary batteries described above. For example, some potential applications require battery activation times not in excess of one second at -40.degree. C and not in excess of 250 milliseconds at -20.degree. C. These rapid activation times cannot be accomplished by existing primary batteries of the type described above except through the use of expensive auxiliary equipment and/or techniques.
Accordingly, it would be desirable to provide a primary battery of the remotely activated type which would exhibit an activation time at lower temperatures which would meet potential application requirements and which would be substantially less than comparable existing primary batteries of the same type. Such primary batteries exhibiting the reduced activation time should preferably be simple and inexpensive and not require the use of auxiliary equipment and/or techniques.